Dry Run IA 02-CED-554
mouth (S18 T89N R13W Black Hawk Co.) to confluence with unnamed tributary in S23 T89N R14W BlackHawk Co
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 10/27/2025 3:09:34 PM
- Updated
- 11/20/2025 10:00:41 AM
The Class A1 use was assessed as "not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as "not supported" based on biological sampling data.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description CRWQ 23 WQ CY 2022-2024 99990068 Dry
Run Creek
Iowa DNR 6 BIO See Below 215 Dry
Run Creek DS
of Waterloo RD – DRC1 Iowa DNR 6 BIO See Below 455 Dry
Run Creek US
of University AVE near UNI Campus – DRC4 Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples per Year (2022/ 2023/2024) 2022 Geometric Mean 2023 Geometric Mean 2024 Geometric Mean Violates Annual Geometric Mean? # 2022 SSM violations / SSM Violations needed for impairment # 2023 SSM violations / SSM Violations needed for impairment # 2024 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 99990068 23 5/5/5 184 91 585 YES 2 / NA 2 / NA 4 / NA YES EVALUATED NOT Class A1 – pH: Site ID Data Source ID # Samples / # Years Minimum Value Maximum Value Mean Value # Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 99990068 23 14 / 3 7.74 8.62 8.16 0 4 NO MONITORED FULL Class BWW2 - Binomial Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value # Violations # Acute / Chronic Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 99990068 23 Chloride 15 / 3 35.6 86 50.5 NA 0 / 0 4 NO MONITORED FULL 99990068 23 Dissolved Oxygen 15 / 3 4.2 15.3 9.7 1 NA / NA 4 NO MONITORED FULL 99990068 23 pH 14 / 3 7.74 8.62 8.16 0 NA / NA 4 NO MONITORED FULL 99990068 23 Sulfate 15 / 3 23.3 37.7 28.4 0 NA / NA 4 NO MONITORED FULL 99990068 23 Temperature 15 / 3 7.6 23.2 17.8 0 NA / NA 4 NO MONITORED FULL Class BWW2 -
Biological Sampling: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47c BMIBI BIT BMIBI Pass/Fail 215 7/26/23 23.7 47c MS Hess 53 Fair 70 Fail 455 7/26/23 9.4 47c MS Hess 48 Fair 70 Fail 215 8/24/21 23.7 47c MS Hess 48 Fair 70 Fail 455 8/24/21 9.4 47c MS Hess 52 Fair 70 Fail BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 47c FIBI BIT FIBI Pass/Fail 215 7/26/23 23.7 47c MS/WW No 71 Excellent 44 Pass 455 7/26/23 9.4 47c MS/WW Yes 57 Good 65 Fail 215 8/24/21 23.7 47c MS/WW No 60 Good 44 Pass 455 8/24/21 9.4 47c MS/WW Yes 60 Good 65 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic Macroinvertebrates Monitored Fail (0/4) Not Fish Monitored Fail (2/4) Not Assessment was monitored because it was completed Overall Monitored Fail Not 5bv using samples collected in a recent five-year period.
Benthic Macroinvertebrates:
Fish:
Overall: